A major side effect of the hypertransfusion treatment for Thalassemia major is accumulation of iron in body tissues, and the primary cause of death for these patients is iron deposition in the heart. The conventional treatment for iron overload consists of daily subcutaneous desferoxamine administration. This study will test the hypothesis that intravenous high-dose desferoxamine over prolonged exposure time can increase the urinary iron excretion, resulting in a lowering of serum ferritin levels in these patients.